FIG. 1 is a conventional method 10 for providing a read transducer. A read sensor is provided, via step 12. The read sensor is on a first shield. The read sensor may be a tunneling magnetoresistive sensor. In addition, the read sensor may have an in-stack NiFe spacer. Such a spacer is typically between the read sensor and a second shield. Magnetic bias structures are provided adjacent to the read sensor, via step 14. In some conventional transducers, the magnetic bias structure includes hard magnetic materials. Typically, the hard bias materials have a capping layer. In more recently developed magnetic transducers, the magnetic bias structure may be a soft magnetic bias structure. A nonmagnetic capping layer is deposited on the portions of the transducers via step 16. The capping layer typically includes Ru and/or Ta. For example, a Ru/Ta bilayer may be used. The capping layer may be used for a chemical mechanical planarization and/or other processing. The top shield is provided, via step 18. Providing the top shield typically includes sputter etching the Ru/Ta capping layer to remove the capping layer and clean the exposed surface.
FIGS. 2 and 3 depict an air-bearing surface (ABS) view of conventional read transducers 50 and 50′, respectively. The conventional read transducer 50 includes shields 52 and 60, sensor 54, in stack NiFe spacer layer 62 and hard magnetic bias structures 58 having capping layer 59. The conventional read transducer 50′ includes shields 52′ and 60′, sensor 54′ and soft magnetic bias structures 58′. The read sensor 54 is typically a giant magnetoresistive (GMR) sensor or tunneling magnetoresistive (TMR) sensor. The read sensor 54 typically includes an antiferromagnetic (AFM) layer, a pinned layer, a nonmagnetic spacer layer, and a free layer.
Although the conventional transducers 50 and 50′ may function, there are drawbacks. The transducer 50 may have nonmagnetic residue 62 between the NiFe spacer 56 and the shield 60. The nonmagnetic residue 62 may include Ta and/or Ru that redeposits during to the method 10. The nonmagnetic residue 62 may magnetically decouple the NiFe spacer layer 56 from the shield 60. Consequently, the effective shield-to-shield spacing may be increased. Similarly, the transducer 50′ may have nonmagnetic residue 62′ between the shield 60′ and soft magnetic bias structure 58′. The nonmagnetic residue 62′ would decouple the magnetically soft bias structures 58′ from the shield 60′. Thus, the performance of the magnetic transducer 50′ would also be adversely affected.
Accordingly, what is needed is a system and method for improving the performance of a magnetic recording read transducer.